Folding chair



June 30, 1942. o, N RZ ETAL 2,288,411

FOLDING CHAIR Filed Aug. 29, 1938 Patented June 30, 1942 FOLDING CHAIR Oscar Liiwenherl, Brussels, Belgium, and Martin Behrens, Cologne, Germany Application August 29 In Germany lClalm.

Our nvention relates to folding chairs and to means for locking coacting parts of such chairs in different relative positions.

It has particular reference to that type of folding chair, in which the seat frame, back frame, a pair of arm rests and the braces supporting the front ends of the arm rests are pivotally connected with each other so as to form adjustable quadrilaterals, one on each side of the chair.

It is an object of our invention to provide means whereby the eoacting parts of such a folding arm chair can be locked in different relative positions in such manner that a simple movement imparted to certain of the coacting parts enables these particular parts to be displaced relatively to others and, on being released, to be locked automatically in the new position.

According to this invention the locking of these parts in an unlimited number of different relative positions is effected by way of a clamping means which replaces the pivotal connection of two adjoining parts in one of the four corners of the adjustable quadrilaterals. By rendering one of these pivotal connections immovable, the entire quadrilateral becomes immovable, and the several parts of the chair are fixed in the position imparted to them. By providing locking means operative by a mere frictional clamping action dependent on the angle between the two parts, it is possible to lock the two parts, and with them also the other parts of the movable quadrilaterals in different positions.

In the drawing aflixed to this specification and forming part thereof a number of folding arm chairs and the means according to this invention for automatically fixing and holding coacting parts of such chair in their relative positions are illustrated diagrammatically by way of example- In the drawing:

Fig. 1 is a perspective view of such chair in unfolded condition, while Figs. 2 and 3 are a plan view and side elevation, respectively, of the same chair in folded condition.

Figs, 4 and 5 are perspective views, drawn to a larger scale, of the means for locking coasting parts of this chair in different positions.

Figs. 6 and 7 are side elevations, in different relative positions of the parts.

Fig. 8 is a perspective view of another folding chair in operative position, while Figs. 9 and 10 illustrate on a larger scale and in two different operative positions the means 1938, Serial No. 227,445 October 22, 1937 for locking coacting parts of this chair in different positions.

Referring to the drawing and first to Figs. 1-5, I are the side members of the seat frame and 2 is the cross bar connecting their front ends. 3 are the side members of the back and 4 are the rear legs, which are pivoted, similarly as the back, to the side members I of the seat, being connected by a cross bar I6. 5 are'the arm rests pivoted to the back and having the fore legs pivoted to their front ends, these legs being connected by a cross bar I and forming braces supporting the front ends of the arm rests. The seat frame, back frame, arm rests and braces on each side of the chair being movably connected.

with each other form an adjustable quadrilateral.

8, 8 are pins or bolts fixed to the fore legs and extending inwardly through slots 9 formed in the side members I of the seat frome. Ill are abutments of angular configuration fixed to the fore legs 6 and spaced from the pins 8 a distance, which is greaterthan the distance between the bottom wall of a slot 9 and the bottom edge of the side member I, i. e. the thickness of the part I2 (Fig. 4) of the side member, in which this slot is provided, so that the part of the side member confined between the slot and the bottom edge can be shifted longitudinally between the bolt 8 and abutment I0, when the fore legs 6 extend at right angles to the side members I. On the other hand, when the fore legs extend at an obtuse angle to the side members I and the abutments II) are applied against the bottom sides of the side members, these latter are clamped between the abutments I0 and bolts 8, as shown in Fig. 1. Obviously the weight of a person seated on the canvas web I3 extending between the cross bars 2 and I4, this latter connecting the top ends of the back frame 3, in tending to enlarge the angle between the side members I and fore legs 6 will force the abutments I0 against the side members I and thereby strengthen the clamping effect. On the other hand a mere raising of the arm rests 5 will cause the bolts 8 to slide freely in the slots 9, so that then the chair can be folded up easily. This locking effect is further increased by the leaning back of the person sitting in the chair, whereby the back frame 3 is turned back and pulls, by way of the arm rests 5, the top ends of the fore legs 6 to the rear.

As shown in Figs. 6 and 7, the bolts 8 and slots 9 may be replaced by other abutments acting on the tops of the side members. In Fig. 6, I1 is a i freely movable side member, l8 a freely movable fore leg, it) an abutment similar to the part it] in Fig. l, but consisting of a lath acting as a check and extending across the front faces oi the pair or iore legs. 2b is another lath acting as a check and extending across the rear faces of the two fore legs, however above the two side members El and the two laths are spaced a distance which is greater than the thickness of the side members it. Thus here again the fore legs are free to be shifted into the vertical posi tion and beyond it until a weight acting on the side members ill creates the tendency oi? enlarging the obtuse angle between the parts and iii) thereby forcing the checlr iii against the under-- side and 2t against the top side or the side members.

A similar locking means is provided in the folding chair or Fig. 8, which is however distinguished from that shown in Fig. i by having seat frame extending beyond the back and forming also the rear legs. Here the side memhere 20 of the seat frame are pivoted to the fore legs 22, which are pivoted again to the arm rests the rear ends or which are pivoted to the back frame 29. The side members 2B or the seat frame, instead of being pivoted to the back frame, extend across and to the rear of the back frame, their rear ends forming rests which replace the rear legs. The side members of the back frame extend below the side members 2i of the seat frame and their bottom ends are connected by a lath 26 extending underneath the two side members 25. Another lath Zll is fixed to the side members oi the back. frame, however on the rear side thereof and above the seat members 2i, which latter is thus confined between the members of the bacl; frame 215 and the two laths 26 and 2?.

Thus, when a person sits down on the seat of this chair, leaning back against the back 3 frame, the lever action exerted by the top halves of the members which turn around the pivot pins til, will force the bottom ends carrying the lath it against the side members 25 from below and the lath 2i against the same members from above, at the same time pulling the arm rests to the rear, whereby the fore legs 22 are pulled back also, being however prevented from turn ing too far, because the two lathe 26 and Eli in locking the side members 29 between them pre vent any further rearward movement or the back 29. Thus the lathe 26 and 2? here act similarly with regard to the seat and baclt, as they did, according to Figs. e and 7 with regard to the seat and tore legs.

In order to be able to vary the relative angu lar position of the seat 26 and bacl; 29 accord= ing to requirements, the seat bars 26 may he formed, on the dersides and near the bash, with wedge races 59 leading to plane iaces 88. The height oi the side bars 2i at the level oi. the races 86B is materially greater than in front of the wedge faces is and therefore the bacl: may be locked in as many difierent positions rel= ative to the seat as are determined by this dif= ierence in height oi the side bars M. The two end positions and the largest and smallest angle are shown in Figs. 9 and ii) respectively.

Various changes may be made in the details disclosed in the foregoing specification without departing from the invention or sacrificing the advantages thereof.

of one of the two parts meeting in the fourth corner of each movable quadrilateral and embracing the other oi said parts, being spaced irorn each other by a distance sumciently exceed ing the thickness oi said other part at the meeting point to allow relative displacement of the parts whenever they extend substantially at right angles to each other.

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